London



A. T. DAWSON AND G. T. BUCKHAM.

BREEOH MECHANISM OF ORDNANCE- APPLICAIION' FILED DEC. 8. M5,.

Patented May 20, 1919.

2 snii'l'S-SHEET I A. T. DAWSONANDG. T. BUCKHAM. BREECH MECHANISM OF ORDNANCE.

APPLICATION HLED DEC. 8. I915.

Patented May 20, 1919.

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ARTHUR TREVOR DAWSON AND GEORGE THOMAS BUCKHAM, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNORS TO VICKERS LIMITED, OF WESTMINSTER,

' LONDON, ENGLAND.

BREECI-I MECHANISM OF ORDNANOE.

I U To all whom it may concern:

way, Westminster, in the county of London, 1 England, have invented certaln new and useful Improvements in or Relating to the .Breech' Mechanism of Ordnance, of which the following is a specification.

*This invention relates to breech mechafnism of the screw type in which the breech screw is rotatably mounted in a carrier (preferably swinging about a vertical hinge bolt or pin) whose rearward and forward movements open and close the breech opening. It has been proposed in such mecha- 'nism to employ a retaining catch mounted on the breech screw carrier and moved into engagement with the breech screw, when the carrier commences its rearward movement, by

a "toe-piece on the catch engaging with a bracket or the like on the gun, the said catch by meeting the face of the breech end of the gun during the inward or closing movement of the carrier, being moved to its dlsengaged position to enablethe breech screw to be locked. In this manner during the rearward and forward movements of the carrier the angular position of the breech screw remains unchanged so that when the breech screw enters the breech chamber there is no liability of the threads on the screw fouling those in the chamber. Such an arrangement of catch results in considerable stress being I placed on parts of the breech actuatmg mechanism during the slamming of the carrier. The chief object of the present 1nvention is to provide a catch which will obviate this disadvantage.

According to this invention the positively actuated retaining catch mounted on the carrier-is adapted to lie in the path of the crank pinion serving to operate thelever or arm connected to the breech screw. I The said catch maybe in the form of a'lever one arm of which lies in a' position transverse to the axis of the gun, and is adapted to engage with an arm or the like on the crank p1n1on.

In order that the said invention may be clearly'understood, and readily carried into 'eifect, we will describe the same more fully Specification of Letters Patent.

Patented May 20, 1919.

with reference to the accompanying drawings in which Figure 1 is a rear elevation and Fig. 2 a sectional plan of a form of the lmproved retaining catch in position on breech mechanism of the kind to which the invention relates, this mechanism being well known and generally similar to that described in the specification of our prior British Patent No. 6485 of 1907; In these figures the breech screw is in the locked pos1t1on. Fig. 3 is a sectional rear elevation showmg a portion of the breech screw carrier and the improved retaining catch ona larger scale than Figs. 1 and 2.

Fig. 4 is a side elevation, viewed from the right hand side of Fig. 3, of the bracket on the gun which serves to move the catch into contact with the arm on the crank pinion when the carrier commences its rearward movement, and

Fig. 5 is a section taken approximately on the line 1, 1 of Fig. 3. In Figs. 3 to 5 the catch is shown in the position it occupies when the breech screw is unlocked.

A is part of the breech screw carrier. B

is the crank pinion of the breech actuating mechanism, this pinion having a roller 6 engaging in a slot or groove 12' in the breech of the gun, in front of which bracket a toe piece 0 on the cranked arm C is situated when the carrieris in its closed position.

The catch C is shown in-Fig. 3 and by full lines in Fig. 5, in the position it occupies when the breech screw carrier is closed and the crank pinion B and the breech screw lever B are shown in-both figures in the position they assume when the breech screw is fully unlocked, the unlocking movement of the breech actuatmg mechanism, havlng been limited as is 'well understood by a stop A Figs. 1 and 2, engaging with a shoulder on the hinge bolt pinion, or by any other suitable device situated between, the carrier C engages. The arm 13 of the crank pinion under these circumstances occupies in relation to the arm C of the catch C, the osition indicated inFig. 3 and in full lines y Fig. 5, the nose piece 0 being situated in a cavity or recess 01 formed in the forward part of the aforesaid bracket D.

lVhen the opening movement of the carrier is commenced-the engagement between the nose piece 0 and an operating surface d* on the bracket D effects a movement of the catch G into the relative position shown by chain lines in :Fig. 5,7-in which position the arm Cof this catchlies against the arm B ofthe crank pinion B; this movement of the catch is limited by a projection 0 there- The catch C may if desired beprovided withaspringG? forjinsuring the continued cooperationbetween the said arms C and B afterthe rearward displacement of the carrier has movedthe toe-piece 0 clear of the bracket D.

Asthe carrier approaches the breech face during the closing movement the toe-piece '0 will, if for any reason the catch C has become partly disengaged from the arni B cooperate with the inclined or rounded rear surface 03 of the bracket D and the catch wilt-thereby be displaced into its fully engaged position. As the closing movement of the carrier isbeing completed, the front surface of the crank arm (P of the catch C will come against the breech face of-the gun and the catch will thus-be displaced 'into lthe po- I ,sition shown by full lines in Fig. 5 with the nose-piecec situated in the recess d of the bracketD. .The arm C then occupiesa position between thebreech screw lever B and the arm 13 sozth'at thecrank pinion can then be displaced to lock the-breech screw.

What we;claim and desire to secure by Letters Patent of the UnitedaStates is 1. In a gun, the combination "with the breech screw, its" carrier and vthe crank'pinion for .angularly movin said breech screw through the intermed1ary of a lever connected to the breech screwand then moving the carrier to the open position without any, previous independent rearward movement of the breech screw, of a movable catch and U a means for positively moving said catch into hinge bolt and the part with which the catch the pathof part'of said crank pinion as the carrier commences its opening movement.

2. In a gun, the combination with the breech screw, its carrier and the crank pinion for angularly moving said breech screw through the intermediary ofa lever connected to the breech screw and then-moving the carrier to the open position without any previous independent rearward movement of the breech screw, of a movable catch-and means for positively moving said catch into the path of part of said crank pinion;,-asthe carrier commences its opening movement, and means for posltively moving saidcatch out of the said path as the carrier completes its closing movement.

In' a gun, the combination with ;the breech screw, its carrierandthe crank pmion for angularly' ,-moving said breech screw. v,

through'the intermediary of a-lever connected to the breech screw and then irnoving the carrier .to the 5 Open vposition without previous independent rearward-movementof the breech screw,-of' a movable catch, an arm on said crank gpinion, and means for positively moving said catch intothe path of said arm when the carrier commences its opening imovement. I

4. .Inagun, the combination :with -the breech screw, itscarrier and the crank pinion 'foryan-gularly moving said breech screw through the intermediaryof ,a-Jlever connected to thefbreech screw and then mov- .ing thecarrier to the open 1p osition without fillYJPIBVlOUS independent-rearward inovement of the breec'hqscrew,-of ;;.a movable catch, an .arm :on 'said crank ,pinion, -,and

means for positively moving said; catch into the path of said arm as, the carrier commences'its opening movement,nand-meansfor V positively moving said catch;outofithe said path as the carrier, completes its closing movement.

:5. In a .gun, the combination with the "breech. screw, its carrier: and-ithe crankpinion for 'angularly movin said breech through the intermed1ary 'ofa ;:1ever oonnected to .the breech screw randithen noving the carrier to theropen position-without 'previoussindependent rearward-m ment f the breech screw, of a catch pivoted insaid carrier, an arm ,on saidcrank ;pinion,,and

bracket on the gun for positively rocking Stud; catch into. engagement with said ar a the :carrlercommences :its opening mov '-ment. 7

6. In EL ggun,- the combination gth breech screw, its; carrier and the crank pinion for actuating said breech screw, of; a catch pivoted i in said carrier, an arm on said {QI'fiJlk pinion, and i a bracket on theggun for; P931 tively rocking said catch into engagement with said arm as the carrier commences its opening movement, said catch being positively rocked into its disengaging position by contact with the breech face of the gun as the carrier completes its closing move ment.

' '7. In a gun, the combination with the c breech screw, its carrier and the crankpinion v for actuating said breech screw, of a two armed lever, a vertical pivot for connecting said lever to the carrier, a projection on said crank pinion with which projection one arm of said lever is adapted to engage, and a bracket on the n for engaging with the other arm of said lever to positively move the first mentioned arm into engagement with the projection on the crank pinion as the carrierv commences its opening movement. I

8. In a gun, the combination with the breech screw, its carrier and the crank pinion for actuating said breech screw, of a two armed lever, a vertical pivot for connecting a said lever to the carrier, a projection on said crank pinion with which projection one arm of said lever is adapted to engage, and a bracket on the gun for engaging with the other arm of said lever to positively move the first mentioned arm into engagement with the projection on the crank pinion as the carrier commences its opening movement, said lever being positively moved into its disengaging position by the contact of the second mentioned arm with the breech face of the gun as the carrier is completing its closing movement.

In testimony whereof we have hereunto aifixed our signatures.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUGKHAM. WVitnesses:

J NO. R. GAswELL, GERTRUDE WHITE.

' Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latentm Washington, D. 0. 

